According to the Minecraft wiki terracotta have hardness of 1.25, which is supposed to be insta-mineable by efficient 5 haste 1 diamond pickaxe since 37.5 is below (8+26)*1.2. But I can’t insta mine terracotta
So I looked into instant mining page on wiki and saw that terracotta was not insta-mineable but basalt could. So I tried with basalt but it didn’t work either